Encapsulation film components and encapsulation films that include the same thing.

Abstract

Invention details;

Description

Composition for encapsulating film and encapsulating film comprising the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2022-0107003, filed August 25, 2022, Korean Patent Application No. 10-2022-0112873, filed September 6, 2022, and Korean Patent Application No. 10-2023-0043750, filed April 3, 2023, the entire contents of which are incorporated herein by reference.

[0003]

[0004] Technology field

[0005] The present invention relates to a composition for a sealing film, a sealing film, and a solar cell module.

[0006]

[0007] As global environmental and energy problems become increasingly serious, solar cells are attracting attention as a means of generating energy without concerns about environmental pollution or depletion. When solar cells are used outdoors, such as on building roofs, they are generally used in the form of solar cell modules. When manufacturing solar cell modules, to obtain a crystalline solar cell module, the following layers are laminated in order: front glass / solar cell encapsulant / crystalline solar cell element / solar cell encapsulant / rear glass (or rear protection sheet). Typically, ethylene / vinyl acetate copolymers or ethylene / alpha-olefin copolymers, which have excellent transparency, flexibility, and adhesiveness, are used as the solar cell encapsulant.

[0008] A solar cell module is a package in which solar cell elements such as silicon, gallium-arsenide, and copper-indium-selenide are protected by an upper transparent protective layer and a lower substrate protective layer, and the solar cell elements and the protective layer are fixed with a sealant. Generally, the sealant for the solar cell elements in a solar cell module is manufactured by extruding an ethylene / alpha-olefin copolymer blended with an organic peroxide or silane coupling agent into a sheet shape, and the solar cell elements are sealed using the obtained sheet-shaped sealant, thereby manufacturing a solar cell module.

[0009] When manufacturing solar cell modules as described above, one approach to improving productivity is to increase the affinity between the various raw materials included in the encapsulant film composition and the ethylene / alpha-olefin copolymer, thereby enhancing absorbency. In particular, crosslinking agents and crosslinking aids, which are essential for the production of encapsulant films, are polar substances and thus inevitably exhibit low absorbency toward the non-polar ethylene / alpha-olefin copolymer. This has been identified as one of the factors causing reduced productivity.

[0010]

[0011] [Prior Art Literature]

[0012] [Patent Document]

[0013] (Patent Document 1) Japanese Patent Publication No. 2015-211189

[0014]

[0015] The purpose of the present invention is to shorten the impregnation time of an ethylene / alpha-olefin copolymer in the initial stage of manufacturing a sealing film and to lower the migration rate of an impregnated crosslinking agent component in a composition for a sealing film.

[0016]

[0017] To solve the above problem, the present invention provides a composition for a sealing film, a sealing film, and a solar cell module.

[0018] (1) The present invention provides a composition for a sealing film, wherein the ratio of the Si-O band integral to the CH band integral (Si-O band integral / CH band integral) calculated from an FT-IR spectrum is 3 to 70.

[0019] (2) The present invention provides a composition for a sealing film having a crosslinking agent migration rate of 4.5% or less, represented by the following mathematical formula 1, when manufacturing a sealing film using the composition for a sealing film and a crosslinking agent in the above (1).

[0020] [Mathematical Formula 1]

[0021] Crosslinking agent migration rate (%) = [Weight of crosslinking agent transferred to the surface of the encapsulating film / Total weight of crosslinking agent] x 100

[0022] In the above mathematical formula 1,

[0023] The weight of the crosslinking agent transferred to the film surface is a value measured after manufacturing a sealing film using the composition for the sealing film and storing it at -5°C for one week.

[0024] The total weight of the above crosslinking agent is the total weight of the crosslinking agent included in the above encapsulating film.

[0025] (3) The present invention provides a composition for a sealing film, wherein, in the above (1) or (2), the ratio of the Si-O band integral to the CH band integral (Si-O band integral / CH band integral) calculated from the FT-IR spectrum is 10 to 50.

[0026] (4) The present invention provides a composition for a sealing film having a crosslinking agent transition rate of 0.1 to 4.3 in any one of the above (1) to (3).

[0027] (5) The present invention provides a composition for a sealing film comprising an ethylene / alpha-olefin copolymer and porous silica in any one of the above (1) to (4).

[0028] (6) The present invention provides a composition for a sealing film in the above (5), wherein the porous silica has an oil absorption of more than 40 mL / 100 g as measured by ASTM D1483-12 (2016).

[0029] (7) The present invention provides a composition for a sealing film in the above (5) or (6), wherein the porous silica has a silanol group-OH content of 1.0 wt% or more based on the total weight of the porous silica.

[0030] (8) The present invention provides a composition for a sealing film, further comprising at least one selected from the group consisting of an organic peroxide, a crosslinking agent, a silane coupling agent, an unsaturated silane compound, an amino silane compound, a light stabilizer, a UV absorber, and a heat stabilizer, in any one of the above (1) to (7).

[0031] (9) The present invention provides a sealing film comprising a composition for a sealing film of any one of the above (1) to (8).

[0032] (10) The present invention provides a solar cell module including the sealing film of (9).

[0033]

[0034] When manufacturing a sealant film using the composition for a sealant film according to the present invention, the impregnation time of the ethylene / alpha-olefin copolymer can be shortened, thereby improving the economic efficiency of the sealant film production process. In addition, by delaying the migration of the crosslinking agent composition component, slippage of the sealant film that may occur during the automated module manufacturing process can be suppressed.

[0035]

[0036] Hereinafter, the present invention will be described in more detail to help understand the present invention.

[0037] The terms or words used in the description and claims of the present invention should not be interpreted as limited to their usual or dictionary meanings, and should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0038]

[0039] <Composition for packaging film>

[0040] The composition for a sealing film of the present invention is characterized in that, when calculated from an FT-IR spectrum, the ratio of the Si-O band integral to the CH band integral (Si-O band integral / CH band integral) is 3 to 70.

[0041]

[0042] The composition for a sealing film of the present invention comprises an ethylene / alpha-olefin copolymer. The ethylene / alpha-olefin copolymer is prepared by copolymerizing ethylene and an alpha-olefin monomer, wherein the alpha-olefin, which refers to a portion derived from the alpha-olefin monomer in the copolymer, is an alpha-olefin having 4 to 20 carbon atoms, specifically, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, or 1-eicosene, and may be one kind alone or a mixture of two or more kinds thereof.

[0043] Among these, the alpha-olefin may be 1-butene, 1-hexene or 1-octene, and preferably 1-butene, 1-hexene or a combination thereof.

[0044] In addition, the content of alpha-olefin in the ethylene / alpha-olefin copolymer may be appropriately selected within a range that satisfies the above-mentioned physical property requirements, and specifically may be 0 to 99 mol%, or 10 to 50 mol%, but is not limited thereto.

[0045] In the present invention, the method or obtaining route for preparing the ethylene / alpha-olefin copolymer is not limited, and a person skilled in the art can select and use an appropriate one considering the properties and purpose of the composition for a sealing film.

[0046] The ethylene / alpha-olefin copolymer included in the composition for the encapsulating film of the present invention may have a density in the range of 0.850 to 0.910 g / cc, wherein the density may refer to a density measured according to ASTM D-792-20. More specifically, the density may be 0.855 g / cc or more, 0.860 g / cc or more, or 0.865 g / cc or more, or 0.870 g / cc or more, and 0.905 g / cc or less, or 0.900 g / cc or less, or 0.895 g / cc or less.

[0047] In general, when using an ethylene / alpha-olefin copolymer in a composition for a sealant film, the lower the density of the copolymer, the lower the crystallinity, which has the advantage of high optical transparency and a short crosslinking agent impregnation time. However, if it is too low, blocking may occur between pellets during pellet storage, making the pellet feeding process difficult, and the copolymer may easily stick to the surface of the take-up roll during sheet forming, which may cause blocking between sheets, which may cause problems with sheet extrusion and various problems may occur in the sheet manufacturing process for a sealant film.

[0048] However, the composition for a sealing film of the present invention is characterized by including an ethylene / alpha-olefin copolymer of the above density, while improving the blocking properties and resistance to stickiness of pellets and sheets, and improving the problem of delayed impregnation time that has accompanied the use of ethylene / alpha-olefin copolymers in the past.

[0049] In addition, the composition for the sealing film of the present invention exhibits excellent compatibility with a crosslinking agent through the silanol group and siloxane group, so that the crosslinking agent component migration rate decreases with time and excellent slip resistance is exhibited on a glass substrate.

[0050]

[0051] The composition for a sealing film of the present invention may include porous silica. By including porous silica, as described above, when calculating the FT-IR spectrum of the composition for a sealing film of the present invention, the ratio of the Si-O band integral to the CH band integral (Si-O band integral / CH band integral) is calculated to be 3 to 70.

[0052] FT-IR (Fourier Transformation-Infrared) equipment is one of the basic spectroscopic equipment and is used to determine the presence or absence of most chemical functional groups. When infrared light is irradiated on a sample, some of the irradiated light is absorbed by the sample and appears as a specific peak. Through this specific peak, the characteristics of the sample can be identified.

[0053] Certain peaks are peaks that appear only in certain functional groups, and the locations of the peaks can be found in the handbook.

[0054] The above Si-O band integral is 1016 cm -1 1247cm in height -1 It can be an integral of the region, and the CH band integral is 1975 cm -1 2110cm in height -1It can be an integral of the domain.

[0055]

[0056] More specifically, the ratio of the Si-O band integral to the CH band integral (Si-O band integral / CH band integral) may be 3 to 70, specifically 4 to 60, or 5 to 50.

[0057] This means that in the composition for the sealing film of the present invention, when the Si-O component in the porous silica is at a certain content or more, there are many sites that can hydrogen bond with the carbonyl group of the crosslinking agent, which can act as a factor that can shorten the impregnation process time by causing an acceleration of the impregnation speed in the crosslinking agent impregnation reaction.

[0058]

[0059] In addition, when manufacturing a sealing film using the composition and crosslinking agent for a sealing film of the present invention, the crosslinking agent migration rate represented by the following mathematical formula 1 may be 4.5% or less.

[0060] [Mathematical Formula 1]

[0061] Crosslinking agent migration rate (%) = [Weight of crosslinking agent transferred to the film surface / Total weight of crosslinking agent] x 100

[0062] In the above mathematical formula 1,

[0063] The weight of the crosslinking agent transferred to the film surface is a value measured after manufacturing a sealing film using the composition for the sealing film and storing it at -5°C for one week.

[0064] The total weight of the above crosslinking agent is the total weight of the crosslinking agent included in the above encapsulating film.

[0065]

[0066] The composition for a sealing film of the present invention comprises porous silica, wherein the porous silica satisfies a certain amount of -OH content of silanol groups and a certain value of specific surface area. The composition for a sealing film of the present invention comprises porous silica satisfies a certain amount of -OH content of silanol groups and a certain value of specific surface area, thereby suppressing the migration phenomenon of a crosslinking agent component and exhibiting a low crosslinking agent migration rate.

[0067] Specifically, the crosslinking agent transition rate represented by the above mathematical formula 1 is 4.5 wt% or less, and specifically may be 0.1 to 4.3 wt%, or 0.5 to 4.3 wt%. By exhibiting a low crosslinking agent transition rate as described above, not only can the physical properties of the encapsulating film be continuously maintained when using it to manufacture an encapsulating film, but also excellent slip resistance can be exhibited on a glass substrate during the solar module manufacturing process.

[0068]

[0069] The composition for a sealing film of the present invention may include an ethylene / alpha-olefin copolymer and porous silica.

[0070] The above porous silica may have an oil absorption of greater than 40 mL / 100g as measured by ASTM D1483-12 (2016).

[0071] Specifically, the absorption amount of the porous silica is greater than 40 mL / 100g, and more specifically, may be 60 to 500 mL / 100g, for example, greater than 40 mL / 100g, 60 mL / 100g or more, 70 mL / 100g or more, 80 mL / 100g or more, 100 mL / 100g or more, 130 mL / 100g or more, and may be 500 mL / 100g or less, 450 mL / 100g or less, 400 mL / 100g or less, 300 mL / 100g or less, or 200 mL / 100g or less.

[0072] The oil absorption of the porous silica used in the present invention falls within the above range, which means that the porous silica has excellent absorbency for a liquid crosslinking agent. In particular, by using porous silica having a high oil absorption of more than 40 mL / 100 g in the present invention, when used in a composition for a sealing film, the porous silica exhibits excellent oil absorption properties for liquid component additives, and the effects of shortening the impregnation time of the crosslinking agent and lowering the crosslinking agent migration rate are exhibited due to the hydrogen bonding effect between the hydroxyl group in the silica and the carbonyl group in the crosslinking agent.

[0073]

[0074] The -OH content of the silanol group (Si-OH) of the above porous silica may be 1.0 wt% or more, and specifically, 1.5 wt% or more, 2.0 wt% or more, 2.5 wt% or more, 3.0 wt% or more, 5.0 wt% or less, or 4.5 wt% or less, based on the total weight of the porous silica.

[0075] When the -OH content of the silanol group satisfies the above range, when a composition for a sealing film including an ethylene / alpha-olefin copolymer and porous silica is stored for a long period of time, the phenomenon of migration toward the surface of the crosslinking agent can be suppressed, and the absorption rate of the crosslinking agent can be improved. When the -OH content of the silanol group is insufficient, the phenomenon of migration of the crosslinking agent can be insufficiently suppressed, and when the -OH content of the silanol group is excessive, moisture in the air can be adsorbed thereto, causing a side reaction when mixing with a crosslinking agent and a silane coupling agent, which can lower the degree of crosslinking and the adhesive strength.

[0076]

[0077] In addition, the specific pore volume of the porous silica may be greater than 0.1 mL / g, and specifically 0.2 to 5.0 mL / g, for example, 0.2 mL / g or more, 0.3 mL / g or more, 0.5 mL / g or more, 0.7 mL / g or more, 5.0 mL / g or less, 3.0 mL / g or less, 2.5 mL / g or less, 2.0 mL / g or less, or 1.0 mL / g or less.

[0078] The specific pore volume of the porous silica used in the present invention falls within the above range, which means that the porous silica has excellent absorbency for a liquid crosslinking agent. In particular, by using porous silica having a large specific pore volume exceeding 0.1 mL / g in the present invention, when used in a composition for a sealing film, the crosslinking agent is efficiently absorbed, resulting in the effect of shortening the impregnation time of the crosslinking agent.

[0079] In addition, the porous silica of the present invention is characterized by simultaneously satisfying the above-mentioned absorption amount and specific pore volume. If either of the two is not within the above range, a problem may arise in which the liquid cross-linking agent is not well absorbed, which may act as a factor that hinders the impregnation of the cross-linking agent.

[0080] In addition, when the porous silica is used, the effect of increasing the volume resistivity also appears. This is because the porous silica acts as an insulator, and this effect appears particularly when the porous silica having the above-mentioned oil absorption and specific pore volume is used.

[0081]

[0082] In the present invention, the porous silica may be present in an amount of 0.1 to 1.5 wt% based on the composition for the sealing film, and specifically, may be present in an amount of 0.1 to 1.0 wt%.

[0083] When the content of porous silica is less than the above range, the effect of efficiently absorbing the liquid cross-linking agent due to the porous silica and shortening the impregnation time of the cross-linking agent through the functional group of the porous silica is minimal, and when the content of porous silica is more than the above range, it may cause an adverse effect of lowering the optical transparency of the encapsulating film.

[0084]

[0085] In the present invention, the porous silica may have an average particle diameter of 1 to 20 µm, and specifically, may be 1.0 µm or more, 1.2 µm or more, 2.0 µm or more, 15.0 µm or less, 14.0 µm or less, 10.0 µm or less, or 5.0 µm or less.

[0086] When the porous silica has the above size, it is well dispersed within the encapsulating sheet, thereby maintaining optical transparency. Furthermore, when the encapsulating sheet is wound and stored, sheet blocking due to the low density of the ethylene / alpha-olefin copolymer can be suppressed. In addition, the average particle size of the porous silica can be suppressed from causing appearance defects due to unevenness on the sheet surface.

[0087]

[0088] In addition, in the present invention, the porous silica has a specific surface area of ​​40 to 800 m 2 / g can be, specifically, 50 m 2 / g or more, 100 m 2 / g or more, 150 m 2 / g or more, 200 m 2 / g or more, 300 m 2 / g or more, 400 m 2 / g or more, 750 m 2 / g or less, 700 m 2 / g or less, 600 m 2 / g or less. When the specific surface area of ​​the porous silica is within the above range, the bond between the silanol group (or OH-containing functional group) of the porous silica and the polar group of the cross-linking agent is efficiently formed, which may result in advantages such as shortening the impregnation time of the cross-linking agent.

[0089]

[0090] The composition for a sealing film of the present invention may further include, in addition to the above-described ethylene / alpha-olefin copolymer and porous silica, at least one selected from the group consisting of known organic peroxides, crosslinking agents, silane coupling agents, unsaturated silane compounds, amino silane compounds, light stabilizers, UV absorbers, and heat stabilizers.

[0091]

[0092] The composition for a sealing film of the present invention comprises a crosslinking agent. In the manufacturing step of a silane-modified resin composition, the crosslinking agent can serve as a radical initiator to initiate a reaction in which an unsaturated silane compound is grafted onto the resin composition. Furthermore, in the lamination step during the manufacturing of an optoelectronic device, the crosslinking agent can form crosslinking bonds between the silane-modified resin composition or between the silane-modified resin composition and the unmodified resin composition, thereby improving the heat resistance and durability of the final product, such as the sealing sheet.

[0093] The crosslinking agent may be any of various crosslinking agents known in the art, as long as it is a crosslinking compound capable of initiating radical polymerization of a vinyl group or forming a crosslinking bond. For example, one or more types selected from the group consisting of organic peroxides, hydroperoxides, and azo compounds may be used.

[0094] For example, a solar cell encapsulating material may include an organic peroxide as a crosslinking agent, and the organic peroxide serves to improve the weather resistance of the solar cell encapsulating material.

[0095] Specifically, dialkyl peroxides such as t-buphylcumyl peroxide, di-t-butyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne; hydroperoxides such as cumene hydroperoxide, diisopropyl benzene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, t-butyl hydroperoxide; diacyl peroxides such as bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide; Peroxy esters such as t-butylperoxy isobutyrate, t-butylperoxy acetate, t-butylperoxy-2-ethylhexylcarbonate (TBEC), t-butylperoxy-2-ethylhexanoate, t-butylperoxy pivalate, t-butylperoxy octoate, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, di-t-butylperoxyphthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne, etc.; and ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, and the like; and azo compounds such as lauryl peroxide, azobisisobutyronitrile, and azobis(2,4-dimethylvaleronitrile), but are not limited thereto.

[0096] The organic peroxide may be an organic peroxide having a 1-hour half-life temperature of 120 to 135°C, for example, 120 to 130°C, 120 to 125°C, preferably 121°C. The "1-hour half-life temperature" refers to a temperature at which the half-life of the crosslinking agent becomes 1 hour. Depending on the 1-hour half-life temperature, the temperature at which the radical initiation reaction efficiently occurs varies, and therefore, when an organic peroxide having a 1-hour half-life temperature in the above-mentioned range is used as a crosslinking agent, the radical initiation reaction, i.e., the crosslinking reaction, can effectively proceed at the lamination process temperature for manufacturing an optoelectronic device.

[0097] The crosslinking agent may be included in an amount of 0.01 to 2 parts by weight, for example, 0.05 to 1.5 parts by weight, 0.1 to 1.5 parts by weight, or 0.5 to 1.5 parts by weight, based on 100 parts by weight of the ethylene / alpha-olefin copolymer. When the crosslinking agent is included in the above range, the effect of improving heat resistance characteristics is sufficiently exhibited, and the formability of the sealing film is also excellent, so that there may be no process restrictions or deterioration of the physical properties of the sealing material.

[0098]

[0099] Cross-linking preparation

[0100] The composition for a sealing film of the present invention may include a crosslinking agent in addition to the crosslinking agent. By including the crosslinking agent in the resin composition, the degree of crosslinking between the resin compositions by the crosslinking agent described above can be increased, thereby further improving the heat resistance and durability of the final product, such as the sealing film.

[0101]

[0102] The crosslinking agent may be any of various crosslinking agents known in the art, and for example, a compound containing at least one unsaturated group such as an allyl group or a (meth)acryloxy group may be used as the crosslinking agent.

[0103] Examples of the compound containing the above-mentioned allyl group include polyallyl compounds such as triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, or diallyl maleate, and examples of the compound containing the above-mentioned (meth)acryloxy group include poly(meth)acryloxy compounds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, or trimethylolpropane trimethacrylate, but are not particularly limited thereto.

[0104] The crosslinking agent is included in an amount of 0.01 to 0.5 parts by weight, for example, 0.01 to 0.3, 0.015 to 0.2, or 0.016 to 0.16 parts by weight, based on 100 parts by weight of the composition for the encapsulating film. When the crosslinking agent is included in an amount of less than 0.01 parts by weight, the effect of improving heat resistance characteristics is minimal, and when it is included in an amount exceeding 0.5 parts by weight, problems may arise that affect the physical properties of the final product, for example, the encapsulating sheet, and the production cost may increase.

[0105]

[0106] silane coupling agent

[0107] The above silane coupling agent can play a role in improving the adhesion between the encapsulant film and the solar cell.

[0108] As the above silane coupling agent, for example, at least one selected from the group consisting of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane (MEMO) may be used, but is not limited thereto.

[0109] The above silane coupling agent may be included in an amount of 0.1 to 0.4 parts by weight based on 100 parts by weight of the composition for the encapsulating film. When the content of the silane coupling agent is within the above range, excellent adhesion to glass is achieved during the manufacture of a solar cell module, thereby preventing long-term performance degradation of the module due to moisture penetration.

[0110]

[0111] In addition, the composition for a sealing film of the present invention may additionally include at least one selected from the group consisting of an unsaturated silane compound, an amino silane compound, a light stabilizer, a UV absorber, and a heat stabilizer.

[0112] The above unsaturated silane compound may be grafted onto a main chain including a polymerization unit of a monomer of the copolymer of the present invention in the presence of a radical initiator or the like, and may be included in a polymerized form in a silane-modified resin composition or an amino-silane-modified resin composition.

[0113] The above unsaturated silane compound may be vinyltrimethoxy silane, vinyltriethoxy silane, vinyltripropoxy silane, vinyltriisopropoxy silane, vinyltributoxy silane, vinyltripentoxy silane, vinyltriphenoxy silane, or vinyltriacetoxy silane, and as an example, vinyltrimethoxy silane or vinyltriethoxy silane may be used, but is not limited thereto.

[0114]

[0115] In addition, the amino silane compound acts as a catalyst that promotes a hydrolysis reaction that converts a reactive functional group, such as an alkoxy group of an unsaturated silane compound grafted onto the main chain of the copolymer, such as vinyltriethoxysilane, into a hydroxyl group in the grafting modification step of the ethylene / alpha-olefin copolymer, thereby further improving the adhesive strength with the back sheet composed of the upper and lower glass substrates or fluororesin. In addition, at the same time, the amino silane compound also participates as a reactant in the direct copolymerization reaction, thereby providing a moiety having an amine functional group to the amino silane-modified resin composition.

[0116] The above amino silane compound is a silane compound containing an amine group, and is not particularly limited as long as it is a primary amine or a secondary amine. For example, amino silane compounds that can be used include aminotrialkoxysilanes, aminodialkoxysilanes, etc., and examples thereof include 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES), bis[(3-triethoxysilyl)propyl]amine, bis[(3-trimethoxysilyl)propyl]amine, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, At least one selected from the group consisting of aminoethylaminomethylmethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethyleneaminomethylmethyldiethoxysilane, (N-phenylamino)methyltrimethoxysilane, (N-phenylamino)methyltriethoxysilane, (N-phenylamino)methylmethyldimethoxysilane, (N-phenylamino)methylmethyldiethoxysilane, 3-(N-phenylamino)propyltrimethoxysilane, 3-(N-phenylamino)propyltriethoxysilane, 3-(N-phenylamino)propylmethyldimethoxysilane, 3-(N-phenylamino)propylmethyldiethoxysilane, and N-(N-butyl)-3-aminopropyltrimethoxysilane. The above amino silane compounds may be used alone or in mixtures.

[0117]

[0118] The above-mentioned light stabilizer may prevent photooxidation by capturing the active species that initiates photodegradation of the resin, depending on the intended use of the composition. The type of light stabilizer that can be used is not particularly limited, and for example, known compounds such as hindered amine compounds or hindered piperidine compounds can be used.

[0119] The above UV absorber can, depending on the use of the composition, absorb ultraviolet rays from sunlight or the like, convert them into harmless heat energy within the molecule, and prevent the active species that initiates photodegradation in the resin composition from being excited. The specific type of UV absorber that can be used is not particularly limited, and for example, one type or a mixture of two or more types of inorganic UV absorbers such as benzophenone-based, benzotriazole-based, acrylonitrile-based, metal complex-based, hindered amine-based, ultrafine titanium oxide-based, or ultrafine zinc oxide-based can be used.

[0120] In addition, examples of the heat stabilizer include phosphorus-based heat stabilizers such as tris(2,4-di-tert-butylphenyl)phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphorous acid, tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4'-diylbisphosphonate, and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite; lactone-based heat stabilizers such as the reaction product of 8-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene, and one or two or more of the above may be used.

[0121] The content of the above-mentioned light stabilizer, UV absorber, and heat stabilizer is not particularly limited. That is, the content of the above-mentioned additives can be appropriately selected in consideration of the intended use of the resin composition, the shape or density of the additives, etc., and can typically be appropriately adjusted within the range of 0.01 to 5 parts by weight based on 100 parts by weight of the total solid content of the composition for the sealant film.

[0122]

[0123] <Bongjijae Film>

[0124] In addition, the present invention provides a sealing film comprising the composition for the sealing film.

[0125] The encapsulating film of the present invention can be manufactured by molding the encapsulating film composition into a film or sheet shape. The molding method is not particularly limited, and for example, it can be manufactured by forming a sheet or film using a conventional process such as a T-die process or extrusion. For example, the manufacturing of the encapsulating film can be performed in situ using a device in which the manufacturing of a modified resin composition using the encapsulating film composition and the film or sheet forming process are interconnected.

[0126] The thickness of the above-mentioned encapsulating film can be adjusted to about 10 to 2,000 ㎛, or about 100 to 1,250 ㎛, taking into consideration the support efficiency and breakage possibility of the element in the optoelectronic device, weight reduction and workability of the device, etc., and can be changed depending on the specific use.

[0127]

[0128] Solar cell module

[0129] In addition, the present invention provides a solar cell module comprising the encapsulant film. In the present invention, the solar cell module may have a configuration in which solar cell cells arranged in series or parallel are spaced apart by the encapsulant film of the present invention, a glass surface is arranged on the side that receives sunlight, and the back surface is protected by a back sheet, but is not limited thereto, and various types and shapes of solar cell modules manufactured including the encapsulant film in the relevant technical field can all be applied to the present invention.

[0130] The above glass surface may be made of tempered glass to protect the solar cell from external impact and prevent breakage, and may be made of low iron tempered glass to prevent reflection of sunlight and increase the transmittance of sunlight, but is not limited thereto.

[0131] The above backsheet is a weather-resistant film that protects the back surface of the solar cell module from the outside, and includes, but is not limited to, a fluorine-based resin sheet, a metal plate or metal foil such as aluminum, a cyclic olefin-based resin sheet, a polycarbonate-based resin sheet, a poly(meth)acrylic-based resin sheet, a polyamide-based resin sheet, a polyester-based resin sheet, and a composite sheet in which a weather-resistant film and a barrier film are laminated.

[0132] In addition, the solar cell module of the present invention can be manufactured without limitation according to a method known in the art, except that it includes the aforementioned encapsulant film.

[0133] The solar cell module of the present invention is manufactured using a sealing film having excellent volume resistivity, and can prevent electrons within the solar cell module from moving through the sealing film and current from leaking out to the outside, thereby significantly suppressing the PID (Potential Induced Degradation) phenomenon in which insulation deteriorates, leakage current occurs, and module output rapidly decreases.

[0134]

[0135] Example

[0136] Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention solely to these examples.

[0137]

[0138] Manufacturing Example 1: Preparation of Transition Metal Compound 1

[0139] <N-tert-부틸-1-(1,2-디메틸-3H-벤조[b]시클로펜타[d]티오펜-3-일)-1,1-디메틸실란아민의 합성>

[0140]

[0141] 4.65 g (15.88 mmol) of chloro(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)dimethylsilane was weighed and added to a 100 ml Schlenk flask, and 80 ml of THF was added. tBuNH2 (4 eq, 6.68 ml) was added at room temperature, and the mixture was reacted at room temperature for 3 days. After the reaction, THF was removed and the residue was filtered with hexane. After drying the solvent, a yellow liquid was obtained in a yield of 4.50 g (86%).

[0142] 1 H-NMR (in CDCl3, 500 MHz): 7.99(d, 1H), 7.83(d, 1H), 7.35(dd, 1H), 7.24(dd, 1H), 3.49(s, 1H), 2.37(s, 3H), 2.17(s, 3H), 1.27(s, 9H), 0.19(s, 3H), -0.17(s, 3H).

[0143] <Preparation of Transition Metal Compounds>

[0144]

[0145] The above ligand compound (1.06 g, 3.22 mmol / 1.0 eq) and MTBE 16.0 mL (0.2 M) were placed in a 50 mL Schlenk flask and stirred first. n-BuLi (2.64 mL, 6.60 mmol / 2.05 eq, 2.5 M in THF) was added at -40 °C and reacted overnight at room temperature. After that, MeMgBr (2.68 mL, 8.05 mmol / 2.5 eq, 3.0 M in diethyl ether) was slowly added dropwise at -40 °C, and then TiCl 4(2.68 ml, 3.22 mmol / 1.0 eq, 1.0 M in toluene) were sequentially added and reacted overnight at room temperature. The reaction mixture was then filtered through Celite using hexane. After drying the solvent, a brown solid was obtained with a yield of 1.07 g (82%).

[0146] 1 H-NMR (in CDCl3, 500 MHz): 7.99(d, 1H), 7.68(d, 1H), 7.40(dd, 1H), 7.30(dd, 1H), 3.22(s, 1H), 2.67(s, 3H), 2.05(s, 3H), 1.54(s, 9H), 0.58(s, 3H), 0.57(s, 3H), 0.40(s, 3H), -0.45(s, 3H).

[0147]

[0148] Manufacturing Example 2: Preparation of Transition Metal Compound 2

[0149] <N-tert-부틸-1-(1,2-디메틸-3H-벤조[b]시클로펜타[d]티오펜-3-일)-1,1-(메틸)(2-메틸페닐)실란아민의 합성>

[0150]

[0151] (i) Preparation of chloro-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(2-methylphenyl)silane

[0152] A 250 mL Schlenk flask was charged with 2.0 g (1.0 eq, 9.985 mmol) of 1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophene and 50 mL of THF, and 4.2 mL (1.05 eq, 10.484 mmol, 2.5 M in hexane) of n-BuLi was added dropwise at -30°C, and the mixture was stirred at room temperature overnight. The stirred Li-complex THF solution was cannulated into a Schlenk flask containing 2.46 g (1.2 eq, 11.982 mmol) of dichloro(O-tolylmethyl)silane and 30 mL of THF at -78°C, and the mixture was stirred at room temperature overnight. After stirring, the mixture was vacuum-dried and extracted with 100 mL of hexane.

[0153] (ii) Preparation of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(2-methylphenyl)silanamine

[0154] 4.0 g (1.0 eq, 10.0 mmol) of extracted chloro-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(2-methylphenyl)silane was stirred in 10 mL of hexane, and then 4.2 mL (4.0 eq, 40.0 mmol) of t-BuNH2 was added at room temperature, followed by stirring overnight at room temperature. After stirring, the mixture was vacuum-dried and extracted with 150 mL of hexane. After drying the solvent, 4.26 g (99%, dr = 1:0.83) of a sticky liquid was obtained.

[0155] 1H-NMR (CDCl3, 500 MHz): δ 7.95(t, 2H), 7.70(d, 1H), 7.52(d, 1H), 7.47-7.44(m, 2H), 7.24-7.02(m, 9H), 6.97(t, 1H), 3.59(s, 1H), 3.58(s, 1H), 2.50(s, 3H), 2.44(s, 3H), 2.25(s, 3H), 2.16(s, 3H), 2.06(s, 3H), 1.56(s, 3H), 1.02(s, 9H), 0.95(s, 9H), -0.03(s, 3H), -0.11(s, 3H)

[0156] <Preparation of Transition Metal Compounds>

[0157]

[0158] In a 250 mL round bottom flask, N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(2-methylphenyl)silanamine (4.26 g, 10.501 mmol) prepared above was added to 53 mL (0.2 M) of MTBE and stirred. At -40°C, n-BuLi (8.6 mL, 21.52 mmol, 2.05 eq, 2.5 M in hexane) was added and stirred at room temperature overnight.

[0159] Afterwards, MeMgBr (8.8 mL, 26.25 mmol, 2.5 eq, 3.0 M in diethyl ether) was slowly added dropwise at -40°C, followed by sequential addition of TiCl4 (10.50 mL, 10.50 mmol) and stirring at room temperature overnight. The reaction mixture was then filtered using hexane.

[0160] DME (3.3 mL, 31.50 mmol) was added to the filtrate, and the solution was filtered and concentrated in hexane to obtain 3.42 g (68 %, dr = 1:0.68) of a yellow solid.

[0161] 1H NMR (CDCl3, 500 MHz): δ 7.83 (d, 1H), 7.80 (d, 1H), 7.74 (d, 1H), 7.71 (d, 1H), 7.68 (d, 1H), 7.37 (d, 1H), 7.31-6.90 (m, 9H), 6.84(t, 1H), 2.54(s, 3H), 2.47(s, 3H), 2.31(s, 3H), 2.20(s, 3H), 1.65(s, 9H), 1.63(s, 9H), 1.34(s, 3H), 1.00(s, 3H), 0.98(s, 3H), 0.81(s, 3H), 0.79(s, 3H), 0.68(s, 3H), 0.14(s, 3H), -0.03(s, 3H)

[0162]

[0163] Manufacturing Example 3: Manufacturing of ethylene / alpha-olefin copolymer

[0164] A 1.5 L continuous process reactor was preheated to 150°C while hexane solvent was fed at a rate of 7 kg / h and 1-butene at a rate of 1.05 kg / h. A mixture of triisobutylaluminum compound (0.05 mmol / min), transition metal compound 1 obtained in Preparation Example 1 and transition metal compound 2 obtained in Preparation Example 2 in a molar ratio of 2.3:1, and dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (1.5 μmol / min) were simultaneously fed into the reactor in an equivalent ratio of 1:1.2. Subsequently, ethylene (0.87 kg / h), butene (1.05 kg / h), and hydrogen gas (20 cc / min) were fed into the reactor, and the copolymerization reaction was carried out by maintaining the temperature at 135.0°C for more than 60 minutes in a continuous process at a pressure of 89 bar, thereby obtaining a copolymer. After drying in a vacuum oven for more than 12 hours, the physical properties were measured.

[0165] The physical properties of the ethylene / alpha-olefin copolymer of Manufacturing Example 3 manufactured in Table 1 below are shown. The physical properties of the copolymer were measured as follows.

[0166]

[0167] 1) Density

[0168] Measured using ASTM D-792-20.

[0169]

[0170] 2) Melt index (MI) and melt flow rate ratio (MFRR)

[0171] ASTM D-1238-04[Condition E, MI 10 (190℃, 10kg load), MI 2.16 MI according to (190℃, 2.16kg load)] 10 and MI 2.16 MI by measuring 2.16 was described as the melting index. Then, MI 10 to MI 2.16 The melt flow rate ratio (MFRR) was calculated by dividing by .

[0172] Density (g / cc) MI (dg / min) MFRR 0.87 37 14.7 6.9

[0173] Example 1

[0174] 99.9 wt% of the ethylene / alpha-olefin copolymer obtained in the above manufacturing example 3 and 0.1 wt% of porous silica (absorbency 149 mL / 100 g, specific pore volume 0.82 mL / g, average particle diameter D 50 2.13 ㎛, specific surface area 554 m 2 / g) was mixed and extrusion blended to pelletize the sample. Then, 500 g of the pellets were placed in a Planetary Mixer of Thermo Electron (Karlsruhe) GmbH preheated to 40°C, and 1.3 phr (parts per hundred rubber) of t-butyl 1-(2-ethylhexyl)monoperoxycarbonate (TBEC), 0.65 phr of triallyl isocyanurate (TAIC), and 0.26 phr of methacryloxypropyltrimethoxysilane (MEMO) were added as additives, and then the mixture was impregnated with the additives while stirring at 40 rpm.

[0175] Afterwards, a sealing film having an average thickness of 550 ㎛ was manufactured using a T-die extruder at a low temperature (extruder barrel temperature of 100°C or less) that did not allow high-temperature cross-linking.

[0176] Crosslinking agent impregnation was performed using a Planetary Mixer from Thermo Electron (Karlsruhe) GmbH. 0.5 phr of triallyl isocyanurate (TAIC) and 0.2 phr of methacryloxypropyltrimethoxysilane (MEMO) were added to 500 g of ethylene / alpha-olefin copolymer, and the mixture was stirred at 40°C and 40 rpm for a sufficient time to allow the crosslinking additives to be absorbed into the ethylene / alpha-olefin copolymer. The change in torque value over time was observed, and the impregnation was terminated when the torque value increased rapidly.

[0177]

[0178] Example 2

[0179] 99.7 wt% of the ethylene / alpha-olefin copolymer obtained in the above manufacturing example 3 and 0.3 wt% of porous silica (absorbency 152 mL / 100 g, specific pore volume 0.78 mL / g, average particle diameter D 50 2.10 ㎛, specific surface area 552 m 2 A sealing film was manufactured in the same manner as in Example 1, except that / g) was used.

[0180]

[0181] Example 3

[0182] 99.5 wt% of the ethylene / alpha-olefin copolymer obtained in the above manufacturing example 3 and 0.5 wt% of porous silica (absorbency 148 mL / 100 g, specific pore volume 0.83 mL / g, average particle diameter D 50 2.16 ㎛, specific surface area 556 m 2 A sealing film was manufactured in the same manner as in Example 1, except that / g) was used.

[0183]

[0184] Example 4

[0185] 99.3 wt% of the ethylene / alpha-olefin copolymer obtained in the above manufacturing example 3 and 0.7 wt% of porous silica (absorbency 146 mL / 100 g, specific pore volume 0.84 mL / g, average particle diameter D 50 2.11 ㎛, specific surface area 557 m 2 A sealing film was manufactured in the same manner as in Example 1, except that / g) was used.

[0186]

[0187] Example 5

[0188] 99.0 wt% of the ethylene / alpha-olefin copolymer obtained in the above manufacturing example 3 and 1.0 wt% of porous silica (absorbency 150 mL / 100 g, specific pore volume 0.79 mL / g, average particle diameter D 50 2.06 ㎛, specific surface area 549 m 2 A sealing film was manufactured in the same manner as in Example 1, except that / g) was used.

[0189]

[0190] Comparative Example 1

[0191] A sealing film was manufactured in the same manner as in Example 1, except that 100 wt% of the ethylene / alpha-olefin copolymer obtained in Manufacturing Example 3 was used.

[0192]

[0193] Comparative Example 2

[0194] 98.0 wt% of the ethylene / alpha-olefin copolymer obtained in the above manufacturing example 3 and 2.0 wt% of porous silica (absorbency 145 mL / 100 g, specific pore volume 0.85 mL / g, average particle diameter D 50 2.07 ㎛, specific surface area 552 m 2 A sealing film was manufactured in the same manner as in Example 1, except that / g) was used.

[0195]

[0196] Comparative Example 3

[0197] 95.0 wt% of the ethylene / alpha-olefin copolymer obtained in the above Preparation Example 3 and 5.0 wt% of porous silica (absorbency 141 mL / 100 g, specific pore volume 0.85 mL / g, average particle diameter D 50 2.14 ㎛, specific surface area 556 m 2 A sealing film was manufactured in the same manner as in Example 1, except that / g) was used.

[0198]

[0199] Experimental Example 1: Method for Measuring the Physical Properties of Silica

[0200] The physical properties of the silica used in the examples and comparative examples were measured using the following method prior to using the silica.

[0201]

[0202] (1) Absorption amount (mL / 100g)

[0203] The oil absorption of porous silica was measured based on the JIS K5101.21 standard method.

[0204]

[0205] (2) Non-pore volume (mL / g)

[0206] The BET specific surface area was measured using BELSORP-mini II (model name) from BEL Japan. After attaching a load and a filter to an empty sample cell to remove moisture, the cell was vacuumed at 150℃, cooled to room temperature, and the weight (a) of the sample cell was measured. 0.05g or more of sample was placed in the cell, the load and filter were attached, the weight was measured, and the cell was vacuumed at 150℃ for 1 hour. After purging to room temperature and pressure, the weight (b) of the sample cell containing the sample was measured. The exact sample weight (ba) obtained through the above process was entered, and the measurement was performed under the conditions of Ads Temp (77K), Sat. vapor pressure (Actural measure), Adsorptive (N2), sample cell diameter (7.0mm), Molec.Dia (0.364nm), Glass rod D (6.0mm), and Ads.P / P0 upper limit (0.3). After measurement, the nitrogen gas adsorption amount was obtained, and the nitrogen gas adsorption / desorption (P / P0, range 0.1 to 0.99) results were calculated using a prescribed method to derive the specific pore volume.

[0207]

[0208] (3) Average particle size (㎛)

[0209] Measurements were made using HELOS KR VIBRI RODOS M (model name) manufactured by SYMPA TEC. An R4 lens capable of measuring particle sizes in the range of 0.5 to 350 μm was used, and the appropriate trigger condition was selected for the sample. First, a reference measurement was taken without a sample to set the device to zero, and then 0.1 to 0.3 g of sample was injected into the funnel and measurement began. When the measurement was completed, D 50 Get the value and the Span value.

[0210]

[0211] (4) Specific surface area (m2 / g)

[0212] The BET specific surface area was measured using BELSORP-mini II (model name) from BEL Japan. After attaching a load and filter to an empty sample cell to remove moisture, the cell was vacuumed at 150°C, cooled to room temperature, and the weight (a) of the sample cell was measured. More than 0.05 g of sample was placed in the cell, the load and filter were attached, the weight was measured, and the cell was vacuumed at 150°C for 1 hour. After purging to room temperature and pressure, the weight (b) of the sample cell containing the sample was measured. The exact sample weight (ba) obtained through the above process was entered, and the measurement was performed under the conditions of Ads Temp (77K), Sat. vapor pressure (Actural measure), Adsorptive (N2), sample cell diameter (7.0 mm), Molec. Dia (0.364 nm), Glass rod D (6.0 mm), and Ads. P / P0 upper limit (0.3). After measurement, the nitrogen gas adsorption amount was obtained to calculate the BET specific surface area.

[0213]

[0214] (5) Silanol group -OH content (weight%)

[0215] Measurements were performed using a Mettler Toledo TGA. The pan was placed on the autosampler, the tare function was activated to zero the instrument, and 4–6 mg of sample was weighed and placed in the pan. Measurements were performed under conditions where N2 gas flowed at 50 mL / min. The temperature was initially stabilized at 30°C, increased by 30°C / min to 150°C. The temperature was maintained at 150°C for 30 min to completely remove any remaining moisture, and then increased by 30°C / min to 950°C.

[0216] The weight of silica excluding moisture (c) was calculated by subtracting the weight reduced from 30°C to 150°C (b) from the total weight of silica (a). The weight reduced from 150°C to 950°C (d) was divided by the weight of silica excluding moisture (c) to measure the content of -OH groups of silanol groups in silica.

[0217] Porous silica content (wt%), oil absorption (mL / 100g), specific pore volume (mL / g), average particle diameter D 50 (㎛) specific surface area (m) 2 / g) Silanol group -OH content (weight %)Example 10.11490.822.135543.5Example 20.31520.782.105523.6Example 30.51480.832.165563.7Example 40.71460.842.115573.4Example 51.01500.792.065493.7Comparative Example 1------Comparative Example 22.01450.852.075523.4Comparative Example 35.01410.862.145563.6

[0218]

[0219] Experimental Example 2: Si-O band integral / CH band integral

[0220] The ethylene / alpha-olefin copolymers used in the above examples and comparative examples were made into sheets of about 0.5 mm thickness through T-die molding without a crosslinking agent, and then analyzed in transmission mode using an Invenio S (Bruker) FT-IR. After inserting the sample into a 10 mm aperture, the 4 cm -1 Resolution, wavenumber 400cm under the condition of 32average -1 at 4000cm -1 The infrared absorbance of the region was measured. After obtaining the silica characteristic peak area for each sample, the normalized Si-O band area was calculated by dividing it by the reference peak area corresponding to the CH band to correct for thickness deviation.

[0221] At this time, the integration method is Si-O band wavenumber 1247cm -1 1016cm at -1 The region was integrated, and the CH band was 2110 cm -1 1975cm in -1 The domain was integrated.

[0222] Si-O band integral CH band integral Integral ratio (Si-O band integral / CH band integral) Example 1 44.95 7.72 85.816 Example 2 98.62 17.50 713.138 Example 3 16 8.37 88.05 820.896 Example 4 224.59 37.89 528.448 Example 5 321.59 17.62 142.194 Comparative example 1 18.73 57.67 22.442 Comparative example 2 608.07 87.54 280.626 Comparative example 3 1491.29 97.49 5 198.973

[0223] As shown in Table 3 above, Examples 1 to 5 are compositions for encapsulating films having an integral ratio of 3 to 70, and Comparative Examples 1 to 3 fall outside the above range.

[0224]

[0225] Experimental Example 3

[0226] (1) Cross-linking system implementation rate

[0227] The encapsulating film (10 cm x 10 cm) manufactured in the examples and comparative examples was left in a -5°C chamber for one week to promote the migration of the crosslinking agent. The encapsulating film was washed in cold MeOH to wash away the additives that had migrated to the surface of the encapsulating film with MeOH.

[0228] The MeOH from which the sealant film was washed was vacuum distilled to evaporate the solvent, and the residual cross-linking agent was obtained. The weight of the cross-linking agent was measured and divided by the weight of the cross-linking agent used in the examples and comparative examples to calculate the transfer ratio (Mathematical Formula 1 below).

[0229] [Mathematical Formula 1]

[0230] Crosslinking agent migration rate (%) = [Weight of crosslinking agent transferred to the surface of the encapsulating film / Total weight of crosslinking agent] x 100

[0231] In the above mathematical formula 1,

[0232] The weight of the crosslinking agent transferred to the film surface is a value measured after manufacturing a sealing film using the composition for the sealing film and storing it at -5°C for one week.

[0233] The total weight of the above crosslinking agent is the total weight of the crosslinking agent included in the above encapsulating film.

[0234]

[0235] (2) Slip resistance

[0236] The encapsulating film (10 cm x 10 cm) manufactured in the examples and comparative examples was left in a -5°C chamber for one week to promote the migration of the additives. Thereafter, the encapsulating film was taken out of the chamber and placed on a 45° inclined glass substrate (3.2T embossed low-iron glass), and the distance moved for one minute was measured, which is shown in Table 5 below. Since the slip phenomenon of the encapsulating film is accelerated by the transferred cross-linking agent compositions, the migration distance of the encapsulating film increases as the transferred cross-linking agent increases.

[0237]

[0238] (3) Impregnation time

[0239] When ethylene / alpha-olefin copolymer pellets and three components of a liquid cross-linking agent are introduced into a planetary mixer and stirred, the cross-linking agent acts as a lubricant until the liquid cross-linking agent is completely absorbed into the pellets, so that the torque value (Nm) applied to the mixing blade according to the soaking time remains constant. After that, when the cross-linking agent is completely absorbed into the pellets, the lubricating effect of the cross-linking agent disappears, and the torque value applied to the mixing blade increases rapidly. The inflection point at this time is defined as the impregnation completion time.

[0240] At this time, the soaking operation was performed until the impregnation completion time, and the impregnation rate was calculated to confirm that it was 99% or more, thereby cross-verifying whether the impregnation completion time was properly measured.

[0241] [Formula 1]

[0242] Impregnation rate (%) = {1-(W2-W3) / W1} * 100

[0243] W1(g) = Total weight of crosslinking agent composition

[0244] W2(g) = Weight of the Mujincheon after the impregnation experiment is over and the mixing bowl, mixing blade, and soaked pellets are wiped.

[0245] W3(g) = Weight of the Mujincheon before starting the impregnation experiment and before cleaning the mixing bowl, mixing blade, and soaked pellets.

[0246] Crosslinking agent transition rateSlip movement distance (mm)Impregnation completion time (min)Impregnation completion time reduction rate (%)Example 14.1015.238.53.8Example 22.109.435.910.3Example 31.506.633.815.5Example 41.105.933.117.3Example 50.805.530.523.8Comparative example 14.5420.140.0-Comparative example 20.705.324.239.5Comparative example 30.604.821.845.5

[0247] As shown in Table 4 above, the composition for the encapsulating film of Comparative Example 1 had a high crosslinking agent transfer rate and thus a long slip movement distance.

[0248]

[0249] Experimental Example 4

[0250] (1) Lamination process

[0251] To measure the optical properties and volume resistivity of the above-mentioned sealant film after crosslinking, a lamination process was performed. Specifically, a laminated sheet was obtained by maintaining the process at a temperature of 150°C for a total of 20 minutes (vacuum 5 minutes / pressure 1 minute / pressure duration 14 minutes).

[0252]

[0253] (2) Light transmittance

[0254] The light transmittance (380–1,100 nm) of the laminated sheet in the visible light range was measured using a Shimadzu UV-3600 spectrophotometer (measurement mode: transmittance, wavelength interval: 1 nm, measurement speed: medium).

[0255]

[0256] (3) Haze

[0257] According to the American Society for Testing and Materials standard ASTM D1003-21, the degree of light refracted (%) when light was shone on 1T (1 mm) of the laminated sheet was measured. Haze was measured as the transparency of the specimen by Td (refracted light) / Tt (transmitted light) x 100 (%).

[0258]

[0259] (4) Volume resistivity

[0260] According to the American Society for Testing and Materials standard ASTM D257-07, the laminated sheet was placed in a Keithley 8009 test fixture under conditions of 23±1℃ temperature and 50±3% humidity, and a voltage of 1000 V was applied for 600 seconds using a Keithley 6517B electrometer connected thereto, and the measurement was performed.

[0261]

[0262] (5) Cross-linking characteristics

[0263] Crosslinking properties were measured using Alpha Technologies' Premier MDR according to ASTM D5289-19A. The test was performed at 150°C for 20 minutes, and a time-dependent torque curve was obtained. The 150°C condition corresponds to the lamination temperature, and the 20 minutes corresponds to the lamination time. Furthermore, the difference between the maximum torque (MH) and minimum torque (ML) applied by the MDR during this time was used to compare crosslinking properties among samples.

[0264] Light transmittance (%T) Haze Volume resistivity (Ωcm) MH-ML (dNm) Example 192.4 1.2 1.9 × 10 17 3.52 Example 292.51.41.6×10 17 3.49 Example 392.31.52.9×10 17 3.51 Example 492.01.53.5×10 17 3.36 Example 591.91.64.3×10 17 3.21 Comparative example 191.91.18.0×10 16 3.53 Comparative example 290.87.33.8×10 17 1.94 Comparative example 389.350.41.4×10 17 0.41

[0265] As shown in Table 5 above, it was confirmed that the compositions for encapsulating films of Comparative Examples 2 and 3 had low light transmittance and high haze, making them unsuitable for use as encapsulating films, and that their crosslinking properties were also deteriorated. In addition, the compositions for encapsulating films of Examples 1 to 5 according to the present invention exhibited superior volume resistivity compared to Comparative Example 1.

Claims

DEPCT681. Encapsulation film composition in which the ratio of the Si-O band integral to the CH band integral (Si-O band integral / CH band integral) is 3 to 70 when calculated from the FT-IR spectrum.

2. Encapsulation film composition of claim 1 in which, when the encapsulation film composition and crosslinker are used to produce the encapsulation film, the crosslinker transfer rate, as shown by Equation 1 below, is at most 4.5 percent: [Equation 1] Crosslinker transfer rate (percent) = [Weight of crosslinker transferred to the encapsulation film surface / Total weight of crosslinker] x 100, where, in Equation 1 above, the weight of crosslinker transferred to the film surface is the value measured after the production of the encapsulation film using the encapsulation film composition and then storing the encapsulation film at -5°C for one week, and the total weight of crosslinker is the total weight of crosslinker included in the encapsulation film. 3.

1. Encapsulation film composition of claim 1 where the ratio of the Si-O band integral to the CH band integral (Si-O band integral / CH band integral) is 4 to 60 when calculated from the FT-IR spectrum.

4. Encapsulation film composition of claim 1 where the crosslinking transfer rate is 0.1 to 4.

3.

5. Encapsulation film composition of claim 1 where the encapsulation film composition consists of an ethylene / alpha-olefin copolymer and porous silica.

6. Encapsulation film composition of claim 5 where the porous silica has an oil absorption rate greater than 40 ml / 100 g as measured according to ASTMD1483-12 (2016).

7. Encapsulation film composition of claim 5 where in the porous silica the amount of -OH of silanol groups is at least 1.0 percent by weight relative to the total weight of the porous silica. 8.Encapsulation film components of claim 1, which include at least one additional component selected from a group consisting of organic peroxides, crosslinking agents, silane coupling agents, unsaturated silane compounds, aminosilane compounds, photostabilizers, UV absorbers, and thermal stabilizers; 9. Encapsulation film components of any one of claims 1 through 8; 10. Solar cell modules components of the encapsulation film of claim 9.